Signaling system



L. A. MORTIMER. SIGNALING SYSTEM.

APPLICATION FILED JULY I2, I9l7.

Patented July 12, 1921.

3-5 any of the sources of energy used 111i tele- I To all whom it may concern:

UNITED STATESTHPATENT oFFIcs-i" ftoU'IsAhMoRrIiunR, or lvnw'ifonnn. Y; Assreivon T0 WESTERN ELECTRIC coin- PANY, mconronarnn, or NEW,YORK, 1v; YL, A oonronarro v sie vannve sysrnm.

Be it known that I, LOUISA. MORTIMER, a citizen of the United, States, residing at New York, in the county of New York and State of New York, have invented certain new a and useful Improvements in Signaling Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to signaling systems, and more particularlyto non-interfer ing'systems employing a single pair oflin'e conductors for a plurality of purposes, as,

for example, in composited telephone and telegraph working where it has been. found desirable to be able to signal'anattendant at a telegraph repeaterstation, and to indicate whichline conductor is concerned,;without interfering with the use of tllGllllQfOItBlG- phone and telegraph communlcation. On

busy and important lines,'itis of the utmost importance to make any changes n the cir'- cuit, such as the cutting-in or cutting-out of a repeater, in the shortest possible time, and

for this reason, it isimportanttobe able to signal the attendant sufliciently before the change is to be made to allow him to make all the necessary preparations therefor.

The objects of this invention are to provide a system wherein asignaling circuit uses the sameline conduetors asare used for a composited telephone and telegraph circuit; to provide a signaling dev1ce'for each line conductor which may be selectively energized, and to provide'means for]render-' ing these signaling devices unresponsive to phone and telegraphworking, onto stray or transient currents which :may galn access to the line conductors; r

- In accordance with one feature of thisinvention, an alternating currentrelay is simplexed to a telephone-circuit tocontrol aselective signaling cireuit,rwhereby one or another of axplurality of signaling devices may be actuated, depending upon the nature cuit: for disabling the signaling circuit when telephone signaling current .is impressed upon the lineconductors, or when stray or,

transient currents find theirwayrto the line conductors, due to irregular telegraph working orother causes; Another feature of the invention is the use ,ofa plurality of'slow- Specification of Letters latent. 1113 12, a plication filed July 12, i it a 1917. Serial No. 180,145.

releasing relaysin the signaling circuit,

controlled by an alternating currentfrelay, which is connected in simplex to 'the telephone circuit, whereby asingle application of signaling current, a predetermined period of time by a second application of such current, will cause one of the'signaling devices to be'actuated; while two applications of such current, in succession, within such predetermined period of t1me,"will cause the actuation of a second device. w Y 1 This invention will be more clearly under stood by reference; to the drawing, which.

illustrates diagrammatically one embodi Inent thereof. a l a i on NEW YORK. x

if not followed within In the drawingis shown a coniposited telephone and telegraph-circuit having two telegraph stations A andB; at the former of whichisa source of signaling current'and means to impress this current upon the line conductors-and, at the latter, a selective re ceiving station wit'h'a plurality of signaling devices; Two telephone stations C and D,

with their associated signaling apparatus, areshown connected to either end of the line. Two line conductors, 5 and 6, are shown extendingbetween the telegraph stations A' i and BL: Two telegraph operators sets, 7 and 8,arc represented 'atstations A and B, re-

spectively, adapted to work with ea-chother over line conductor 5 while two similar sets 9 and 10 are adapted to work over'line conductor 6. As is commonfin composite telegraphpractice' each of these setsis connectt ed to its respective lineconductorf and to ground through a retardation coil; 11 and condenser 12respective1y; Condensers 13- isolate "the various sectionsj of the line, so far as telegraph impulses are concerned, while not disturbing the line continuity for telephonic transmission and signaling.

Signaling apparatus, comprising signal sending; means 15, a 1 selective receiving circuit 'lfi and a'disabling circuit 17 areshown atpstation B; while, for] the purpose of Sim plicity,only the signalsending apparatus 15 isshown. at station A. All the apparatus in the drawing isshowh in its "normal quiescent.

condition. g i 1 It is believed that the invention will be clear froma descriptlon'of its operation now I to follow; c a V i, a a i Let it be assumed thatthe attendant at station A wishes to inform the attendant at station B that the J telegraph circuit employing line conductor 5 is to be concerned in some'change. He can do this by actuating the signaling device or lamp 18. By actuating key 20, the attendant will impress signaling current from generator 14 upon line conductors 5 and 6 in parallel to actuate an alternating current relay '19. The circuit for such current extends from-ground at sta tion A, lower engaged contact members (normallyppen) of-key20, generator 1.4, then in parallel paths over the line conductors.

5, 6; to windi'ng 22 of'relay .19; one path extending through upper engaged contact members (normally pen) otkey-20, upper lefthand retardation coil 11 and condenser j 13 at station A, line conductor'5, condenser 13; and upper right-hand retardation coil 11 at station'B, condenser 25,'upfper nor- -mally engagedco-ntact memberscof key 26,

normally engaged contact members .28, 29 of relay 30 and resistance 31; the otheriextending from intermediate engaged contact memberstnormally open) of key 20, lower left-hand retardation coil 11' and condenser 13 of station A,'line conductor 6, condenser 13 and lower right-hand retardation coil'11 of station B, condenser 34, intermediate normally' engaged; contact members of key 26,

normally; engaged contact members 37, 38

of-relay- 30 and resistance 32 thence through windings 22"and 39 of 'relay'19to ground.

, Th ejcondensers 12 are of such capacity that the leakage through them is not'of a sufiicient, amount fa -prevent the operation of relay 19 since this relay is eta-very sensi tive high resistance type and therefore responds to exceptionally low value of cur-' rent, ,The operation ofrelay 19opens the circuit of normally venergized relay 40, allowing its armature 41 to be retracted,

. thereby, disengaging; contact member 42,

and causing the engagement of contact members 42 and 43. Relay44is thereupon ener gizedito cause the engagement of contact membe1s, 41,. 42 and todisengage contact membersa42, 43. Relay .48 is thereupon,

gized over a; circuit 1 from battery 45., nor mally, engaged contact members; of relay 48, "winding,- of relay 44, engaged contacts 43,42 of relay 40,' ;engaged contactam'embers of locking key149 to-grouncl; The actuation' of, relayJ-441oauses the engagement of contact members 50, 51-, and the disengagement of contact members 51, 52. Upon theremoval of signalingicurrent from the circuit at station .A, relay 40 is again enerenergized over a circuit from battery 45,

. winding 53 of relay 48, engaged contact members 50, 51 of relay 44, engaged con tact members 41, 42 of relay 40, through thewengaged contact members of looking 9 key 49 to ground. Its armatures are thereupon-attracted; the lower serving to interv ruptitheenergizing-circuit ofrelay 44 by disengaging the normally engaged back 0011.-

tact member and to partially prepare an energizing circuit for relay'56 by engagement with the lower alternate'contactmemher; the, upper serving to close a locking circuit for relay 48 and to light lamp 18. ,The locking circuit for relay 48 may be traced from battery 58, upper engaged contact members (normally open) and winding of relay 48, through engaged contact members of locking key 49to ground. The lamp 18 is energized over a circuit from battery 58, upper engaged contact members (normally open). 01": relay 48, {upper nor mally erigagedcontactmembers of relay 56,lamp 18, engaged contactmembers 52,

51ofrelay 44, and engaged contact members 41, 42" of relay 40, through engaged contact members of locking key 49 to ground. It isto'be noted that relay 48 can not be energized until relay40 has again become energized, and that lamp 18 cannot be lighted until relay 44 hasbeendeenergized. Relay 44 beinga' slow; release relay,

period of time will elapse betweenthe deenergization of relay 19 and the lighting of lamp 18, depending upon the timeit takes for relay'44 to releaseits armature. Lampv 18 is therefore lighted by a single applica-, tion of signaling current at station A;

tuate signaling device or lamp 63.7 A sec- 'ond application of signaling current will] cause the deener-gization of lamp 18 and,

of lamp'18, by causingthe disengagement of its upper normally engaged contact members, and completes an energizlng circuit forlamp 63 from battery 64, lamp 63, alternate engaged contact members of relay 56 engaged contactm'embers of locking key '49, to ground. -Relay- 56 is locked up as aresultof its actuation," since the energizing circuit of relay 40 is thereby interrupted,

causingithe continuous engagement of con tact members 42,143 thereof; the normally closed energizing. circuit of relay 40 extend ing from battery-67,1 winding of relay 40,

normally engaged contact members of relay 19, lower normally engaged contact mem-' bers (now open) of relay 56, engage'd contactmembers'of locking key 49, to ground. -5

-Ag'ain, in order-to indicate that line conit: is thus evident, that a predetermined w [.95 I In order to indicatethat lineconductor 6;is alsof-concerned,'the attendant Vmay ac-J ductor 6 alone is concerned, lamp 63 alone maybe actuated by two successive applicatlons of the signaling current within a predetermined period of time determined by the time of release of relay 44. Until relay 44 has released its armature 50, the circuit of lamp 18 is interrupted at contact members 51, 52 of relay 44, but relay 48 has already been locked up by the subsequent energization of relay 40 to prepare the energizing circuit of relay 56 by causing engagement of the alternate contact members of relay 48. Therefore, while the first application of signaling current will not actuate the lamp 18 within the abovementioned predetermined period of time, a second application, occurring within that time, will cause lamp 63 to be lighted in the manner hereinbefore described.

The attendant at station B can return all apparatus of the circuit to normal by the disengagement of the contact members of locking key 49, thereby removing the ground connection of each of the relays.

In order to prevent the system from giving false signals due to the signaling current from the telephone system or due to stray or transient currents on the telephone lines, which may find their way to ground through relay 19, a. second alternating current relay 70 is provided, having a pair of normally engaged contact members and havin its windings 73, 74 connected in series ai ing across pointsof equal potential in the two legs of the signaling circuit, hereinbefore described. Such currents, by causing the energization of relay 70, will deenergize relay 30 to disconnect the signaling circuit from the line conductors by the disengagement of contact members-28, 29 and 37, 38 of relay 30. The energizing circuit of relay 30, which is interrupted by the disengagement of the normally engaged contact members of relay 70, extends from battery 75, winding of'relay 30, normally engaged contact members of relay 70, to ground.

In the preferred embodiment of this invention, the source of signaling current 14 is adapted to furnish current of approximately 133 cycles per second; the relays 19 and 7 0 being adapted to respond to current of substantiall the same frequency.

It is, there ore, seen that the attendant at station A can cause the actuation of either of the lamps 18 or 63. He can do this without interfering with the telegraphcommunication between telegraph sets 7 and 8 or 9 and 10, because the telegraph instruments are not responsive to signaling current from generator 14, and without interfering with telephonic communication or signaling between telephone stations C and D, since his signaling current traverses the telephone line conductor in parallel. His own signaling devices, moreover, are not affected by upon the line conductors; due principally to the factthat relay 19 isresponsive only to currents of frequency substantially the same as that. of his signaling current, but also to the fact that his signaling devices are disconnected from the lineconductors by; the

actuation of relay, 70 in other instances where false signals. might be given. What isclaimedis:

. 1. In asignalingsystem, a plurality of signaling devices, a source of signaling current, a.relay responsive to a single applicae tionof current from said source, means operat1vedue to the energlzation of said re-. lay to actuate one of saldcslgnalmg devices and to condition another of said signaling devices, for operation and responsive due toa second energization of said relay by current-from said source to disconnect the first-mentioned signaling device and to actuate the other signaling device. f

2. In a signaling system, a plurality of signaling devices, an operating circuit for each of said devices, a source of signaling current, meansresponsive to a single application of current from said source toact-uate {one of said signaling devices and partly establish the operating circuit for another of said signaling devices and responsive to two successive applications of currentwithin a predetermined length of time to disconnect the first mentioned signaling device and to complete. the operatinggcircuitof the other signaling device.

3. In a signaling system, a plurality signalingdevlces, an operating circuit for each of sa d devices, a source of signaling current, means responsive to a single appli cation of current from said source to select and actuate one of said slgnaling devices and partly establish the operating circuit rent, signal-control means adapted to be ac tuated by said signaling current, other means actuated by a single energization of said signal-control means to operate one of said slgnalmg devices, still other means cooperatlng with said beforementioned means.

actuated by a second energization of said slgnal-control means to operate another of said signaling devices, and a relay cooperating with said other means to prevent the operation of said first mentioned signaling 7 determined period 'tion thereof. 7 I

device if the second energization of said signal-control means. occurs Within a re.- after the first energiza- 5. In a signalingsystem, a plurality of signals, asource of signaling current, a sig, nal-control means adapted to be energized by said signaling current, a relay actuated by a single energization of said signal-control means to actuate one of said signals, a second relay actuated by said single-energization of said signal-control means to delay the actuation of said signal for a l other of said signals.

predetermined length of time, and a third relay cooperating with said first mentioned;

relay adaptedupon a second energization of said signal-control means to actuate ansponsive to said series current to disconnect said signaling apparatus from said line 0011- ductors. V

=7. In a signaling system, apair of line conductors, signaling apparatus connected.

to said line conductors, a source of signaling current adapted to supply current over said l-ine conductors for actuating said signaling apparatus, sources or" current other than saidsource of signaling currentadapt ed to supply current over said line conductors, and means actuated by said last mentioned currents to disconnect the signaling apparatus from the llne conductors; V

8::In a signalingrsystem, a pair: of line conductors, signaling apparatus connected to said line conductors, a source of signalin'gv current adapted to supply current in parallel over said line conductors for actuating said signaling apparatus, another source of current adapted to supply current over said-line conductors in series, arelay responsive to-said'series current, and a second relay adapted to] disconnect the signaling apparatus from said'line conductors upon the actuation of said first mentioned relay.

9. In a signaling system, a plurality of line conductors, signaling apparatus c0n nected thereto, a plurality of sources of current having different electrical character istics adapted to supply current over said lineconductors, means connected to but intermediate said signaling apparatus and said line conductors responsive to current from one of said plurality of sources to dis connect said signaling device from said line conductors but unresponsive to current from another of said plurality of sources.

10. A signaling system comprising a'plurality of signaling devices, a source of signaling current, means responsive to a single v application-of current from said sourcejto actuate one of said-signalmg devices and to condition another of said signaling devices for operation and responsive to tWo successlve applications of current wlthin a1 predetermined period of time from said source to prevent tlieoperation ofthe first mentioned signaling device and to actuate the other signalingdevi'ce. y I In Witness whereof, I hereunto subscribe my name this 9th day of July, AaD. 1917.

c I LOUIS n. MORTIMER. 

